Make seeds for randomgenerators configurable

[mmichaelis]

In order to be able to reproduce test results it is required to log the seed of a random number generation and also provide the ability to adjust the seed during a debugging run.

[mmichaelis]

• The class to change for strings is RandomStringType.
• RandomStringType calls random(5) but should call random(7) instead with the additional arguments:
  1. null for the list of characters.
  2. Random for the random number generator.
• Have to consider if to use Spring for configuration or keep the module spring-less which requires to add a "blind" system property.
• Actually it needs to be straightened to work the same for numbers and strings here.

[mmichaelis]

Actually the approach requires more thoughts to spend:

• Assumption: You have a global Random object with configurable seed.

  If the failed test run ran with seed 1234 for a global Random object, then if you want to reproduce the test it is NOT enough to set the seed to 1234 again:
  This is because the random object might have been used by previous calls, for example other tests. So the actual random value returned for a given test not only depends on the seed but also in the order previous tests ran.

• Assumption: For each random number a new Random object is created.

  In this case we cannot use a configurable/fixed seed. Otherwise if random values are used to prevent collisions between tests (such as document names).

Other requirements are that random number generators should be usable without Spring but preferably with Spring in order to allow more flexible configuration of the property to use to set the seed.

As the architecture is not yet clear, all commits will be reverted. The original random data generators will get a notice that it is not recommended to use them.

[mmichaelis]

RandomGenerator: Project discontinued. Corresponding classes have been marked as deprecated.